KR950010371B1 - Electronic range - Google Patents

Abstract

sensing weight of food upon input of a warming/thawing key by a user and calculating a time point at which warming or thawing of food is discriminated and a thawing time; heating the food during the calculated discrimination time point and sensing temperature by heat of the food heated; if the temperature of food increases over a predetermined value; executing a warming function; if under the predetermined value, executing a thawing function; and completing a cooking procedure in accordance with the warming or thawing function.

Description

Microwave warming / thawing control method

1 is a block diagram showing the configuration of a microwave oven having a general warming / thawing one-key.

2 is an experimental graph of the warming and thawing discrimination according to the weight and height of food in FIG.

3 is a block diagram showing the configuration of a microwave oven having a warming / thawing source-key of the present invention.

4 is a graph showing an example of the detection characteristics of the weight sensor and the temperature sensor of the present invention.

5 is a graph of warming / thawing discrimination characteristics according to the present invention.

Figure 6 is a signal flow diagram for a warming / thawing control method of the microwave oven of the present invention.

* Explanation of symbols for main parts of the drawings

54: control panel 55: microcomputer

57: heating chamber 58: rotary table

59: food 60: weight sensing element

61: rotary table motor 63: weight sensing circuit

64: magnetron 65: drive unit

66: suction guide 67: exhaust guide

68: temperature sensing element 69: temperature sensing circuit

70: cooling fan

The present invention relates to a method for controlling the warming / thawing of a microwave oven, and in particular, by shifting the correlation between the weight of food and the change in temperature of the exhaust temperature indirectly sensing the temperature of the food to determine the warming and thawing by itself to perform automatic cooking. It relates to a warming / thawing control method of a microwave oven.

A block diagram showing the construction of a microwave oven with a conventional warming / thawing one-key is mounted at the bottom in a heating chamber 7 for heating food 9, as shown in FIG. The rotary table 8 rotates so that the food 9 is heated evenly by driving the rotary table motor 11, and is mounted on the lower part of the rotary table motor 11 to sense the weight of the food 9. The weight sensing element 10 is converted into an electrical signal corresponding to the weight sensing circuit unit 13, and the food 9 is located at a predetermined distance from the center of the rotary table 8 on the heating chamber 7. Ultrasonic sensor 6 which transmits the ultrasonic wave to the ultrasonic wave reflected from the food and converts the ultrasonic wave into electrical signal and then transmits the ultrasonic wave to the ultrasonic sensing circuit unit 12 and the overall operation of the microwave oven by the signals input from the respective units. To control the microcomputer And a magnetron 14 for oscillating microwaves into the heating chamber 7 in accordance with a drive signal applied through the driver 15 according to the control signal of the microcomputer 5 and the magnetron 14. Cooling fan 20 for cooling the high heat of the heat sink, suction guide 16 for allowing the air introduced by the cooling fan 20 to be sucked into the heating chamber 7, and the heating chamber 7 Gas and water vapor are discharged out together with the suction air through the suction guide 16, and the amount of water vapor or gas generated from the food (9) to detect the amount of water or gas through the gas detection circuit unit 19 It consists of a gas detector 18 mounted in the exhaust guide 17 to input an electrical signal to the computer 5. In the figure, reference numeral 4 denotes an operation unit for driving the microcomputer 5.

Here, the ultrasonic sensor 6 is mounted at a position L by a distance L from the center of the upper end, the distance from the upper end of the heating table 7 to the rotary table 8 is H, and the height of the food 9 is h.

Referring to the operation of the microwave system having a conventional detent / thaw one-key configured as described above are as follows.

After the food 9 is placed on the rotary table 8 in the heating chamber 7 while the microwave is powered on, the user operates the operation unit 4 and presses the warming / thawing source key. The motor 11 is driven to rotate the rotary table 8 so that the food 9 is rotated.

Then, the weight sensing element 10 mounted below the rotary table motor 11 detects the weight W of the food 9 and transmits an electrical signal corresponding to the detected weight through the weight sensing circuit 13. To the microcomputer 5.

At the same time, the distance from the center of the rotary table 8 in the heating chamber 7 The ultrasonic sensor 6 mounted on the upper side of the heating chamber 7 at a distance from each other is driven by driving signals of the microcomputer 5 and the ultrasonic sensing circuit unit 12 to transmit ultrasonic waves to the food 9 and at the same time. The ultrasonic wave reflected back from the food 9 is received again, the distance d to the surface of the food 9 is calculated, converted into an electrical signal proportional to the calculated distance d, and then the ultrasonic sensing circuit unit ( 12) to the microcomputer (5). Then, the microcomputer 5 receives the signals detected by the weight sensing element 10 and the ultrasonic sensor 6 and performs calculation.

That is, the microcomputer 5 calculates the weight W of the food 9 from the electrical signal sent from the weight sensing element 10, and has a distance d measured from the ultrasonic sensor 6. Calculate the height h of 9). Here, the height h of the food 9 is h = H-d. H is the distance from the surface of the rotary table 8 to the upper end of the heating chamber 7.

Warming and thawing are determined from the graph shown in FIG. 2 with the data for the weight W and the food height h obtained as described above. That is, even in the case of thawing, the height h of the food 9 is relatively high in the case of thawing by using a container such as a thawing network. Therefore, the area above the a dotted line is determined by thawing, and the area below the b dotted line is determined to be warmed.

When it is determined whether it is warmed or thawed, the cooking is performed by a normal automatic cooking method, and the cooking is completed as described below.

In the case of the first heating automatic cooking, when the driving unit 15 applies the driving signal to the magnetron 14 according to the control signal output of the microcomputer 5, the magnetron 14 is driven to introduce microwaves into the heating chamber 7. Occurs. Then, the food 9 is heated by the microwave to generate gas and water vapor.

The gas and water vapor generated in the food 9 are discharged out through the exhaust guide 17 together with the air sucked into the heating chamber 7 through the suction guide 16 by the cooling fan 20. At this time, while the gas detector 18 mounted in the exhaust guide 17 continuously detects the amount of water vapor or gas from the food 9, the gas detector 18 outputs an electric signal corresponding to the detected water vapor and the amount of gas through the gas sensing circuit unit 19. To (5).

Therefore, the microcomputer 5 captures the completion time of cooking while calculating the electrical signal applied through the gas sensing circuit unit 19 and ends the cooking to perform automatic cooking.

Secondly, in the case of thawing automatic cooking, the microcomputer receives the electrical signal corresponding to the food (9) and the weight (W) detected from the weight sensing element 10 at the beginning described in the case of the automatic heating. When (5) is input, the microcomputer 5 calculates a heating time corresponding to the weight W and controls the magnetron 14 by the calculated time to perform automatic thawing.

However, in a microwave oven system having a conventional warming / thawing one-key, an ultrasonic wave is transmitted to the food and the ultrasonic wave reflected from the food is returned according to the surface state of the food when the height of the food placed on the rotating table is measured by rotating the food on the rotating table. Since it is different, accurate measurement is difficult, and even if height is measured, it is easy to cause malfunction to discriminate depending on the shape of a container.

In other words, if there is food with a height that corresponds to thawing during warming, the consumer wants to warm it up, but the microwave performs the thawing function, and when the thawing function is performed without using the thawing network, the height of the food corresponds to the warming. There is a problem that the cooking is messed up because you want to perform the warming.

Therefore, in order to solve the conventional problems, the object of the present invention is to determine the warming and thawing by using the weight of the food and the exhaustion sensing temperature, and more reliable than the indirect method of determining the height of the container or food, such as the thawing network, cooking Since the state of the food during the determination of the process is more accurate than the initial determination method to provide a warming / thawing control method of the microwave oven to increase the reliability of the results of the cooking.

The method for achieving the above object is, as shown in Figure 6, the time calculation for detecting the weight of the food during the warming / thawing one-key input by the user and determining the warming / thawing according to the detected weight and A first step of calculating the thawing time, a second step of sensing the temperature of the food while heating the food during the determination time calculated in the first step, and warming when the temperature of the food increases by more than one temperature in the second step. If the determination is less than or equal to a predetermined value, it comprises a third step of determining thawing, and a fourth step of performing cooking and ending according to the warming and thawing function determined in the third step.

The block configuration of the microwave oven for performing the method consisting of each step in the above, as shown in Figure 3 is mounted on the lower portion in the heating chamber 57 for heating the food (59) of the rotary table motor 61 The rotary table 58 rotates the food 59 by driving, and is mounted on the lower portion of the rotary table motor 61 to sense the weight of the food 59 and transmit an electrical signal corresponding thereto to detect the weight of the food 59. 63, a weight sensing element 60 to be delivered to, the exhaust guide 67 for discharging the gas and water generated from the food in the heating chamber 57 with the suction air through the suction guide 66, A temperature sensing element 68 mounted in the exhaust guide 67 to sense heat generated from the food 59 and input an electrical signal to the microcomputer 55 through the temperature sensing circuit 69; , The weight sensing element 6 0) and the microcomputer 55 which controls the respective systems by performing the discriminating operation for warming and thawing as a signal input from the temperature sensing element 68, and the driver 65 according to the control signal of the microcomputer 55. Magnetron 64 for oscillating microwaves into the heating chamber 57 in accordance with the drive signal applied through the cooling fan, a cooling fan 70 for cooling the high heat of the magnetron 64, and the cooling fan 70 It consists of a suction guide 66 to let the air introduced into the heating chamber (57). In the drawing, reference numeral 54 denotes an operation unit including a warming / thawing source-key.

Referring to the operation and effects of the present invention configured as described above in detail.

After the food is placed on the rotary table 58 of the heating chamber 57 in the state where the microwave is powered on, the user operates the operation unit 54 to press the warm / thaw one-key, A rotary table motor 61 for driving 58 is driven to rotate the rotary table 58 and the food and drink 59.

At the same time, the weight sensing element 60 mounted below the rotary table motor 61 senses the weight W of the food 59 and transmits an electrical signal corresponding to the microcomputer 55 through the weight sensing circuit 63. ).

At this time, the microcomputer 55 drives the magnetron 64 through the driving unit 65 so that microwaves are oscillated in the magnetron 14 to heat the food 59.

Heat generated while the food 59 is heated by the microwaves emitted from the magnetron 64 is discharged to the exhaust guide 67 together with the air sucked through the suction guide 66 by the cooling fan 70. At this time, the temperature sensing element 68 mounted in the exhaust guide 67 continuously detects the heat from the food 59 and applies the corresponding electrical signal to the microcomputer 55 through the temperature sensing circuit 69. Done.

Meanwhile, the microcomputer 55 performs the following warming / thawing determination operation with the electrical signals applied from the weight sensing circuit 63 and the temperature gas sensing circuit 69.

When the warming and thawing cooking is performed in the above process, the characteristics detected by the weight sensing element 60 and the temperature sensing element 68 are shown as shown in FIG. 4, where FIG. When the heating time elapses, the temperature value detected by the other temperature sensing element 68 in the weight (W) of the food (59), but the food (59) tends to decrease the temperature increase rate as the weight (W) increases 4 (b) is a temperature value detected by the temperature sensing element 68 according to the weight (W) of the food 59 with the passage of time when the defrosting function is performed. There is no temperature change, but after curing for a certain period of time, the temperature rises after the completion of the normal thawing, the weight (W) of the food 59 can be seen that the longer the time without the temperature change.

In addition, because thawing takes longer than warming due to the difference in dielectric constant between water and ice, the following equation (1) holds.

t1 <14, t2 <15, 13 <t6 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ (1)

Therefore, in the present invention, a control characteristic graph as shown in FIG. 5 is created to perform automatic cooking by performing warming / thawing discrimination. That is, the time t1, t2, t3 reaching the warming completion temperature Te is shorter than the time t4, t5, t6 when the detected temperature at which the thawing proceeds out of the constant temperature Tc is completed. Therefore, the warming / thawing determination time (t0) is judged with the warming / thawing determination temperature (TO) before the warming completion time (t1, t2, t3), and the warming / thawing is performed to perform the following cooking.

The operation as described above is described in detail with reference to the signal flow diagram of FIG. 6 as follows.

When the warming / thawing one-key is input, the rotary table motor 61 is turned on, and accordingly, the weight sensing element 60 measures the weight W and calculates the warming / thawing discrimination time point t0 according to the weight. After heating up to t0, if the temperature increase (△ TO) is above a certain level, it is determined to warm up, and if it is below a certain value, it is judged to thaw.In the case of warming, the temperature increase (△ Te) reaching the completion temperature (Te) When the temperature reaches a certain value, the warming is completed, and in the case of thawing, the total thawing time (tc) according to the weight (W) of the food is determined at the beginning of heating, except that the time for reaching the warming / thawing determination time point (to) is reached. Automatic thawing by controlling the magnetron 64 by an additional thawing time tadd.

As described in detail above, the present invention determines the warming / thawing by using the food weight (W) and the exhaust gas sensing temperature (T), so that it is more reliable than the indirect method of judging by the height of a container or food, such as a conventional thawing network. Excellent and also because the state is judged during the cooking process is more accurate than the initial determination method has a high effect on the reliability of the cooking results.

Claims (1)

A first step of detecting a weight of food when the warming / thawing one-key is input by the user and determining a warming / thawing time and a thawing time according to the detected weight; and a determination time calculated in the first step A second step of sensing a temperature by using the heat of the food generated at that time while heating the food, and a third step of determining that the food temperature increases by more than a predetermined value in the second step, by heating, and by thawing if it is less than a predetermined value. And a fourth step of performing and ending cooking according to the warming and thawing function determined in the third step.